Dynamo required

[Flash]

Hi, just thought I'd see whether anyone has a spare dynamo for a Matchless G9 1957 model, the one that fits at the front of the engine using a 2BA longish screw. I have trouble with mine in that the screw thread was knackered & someone had bodged it previously, so realy its only the end plate that I require, that fits to the chain case. At the moment I have oil coming out from the joint. I am prepared to buy a new dynamo if possible. Any ideas you lot?

Regards John

[RogerJ]

Is the thread bodged to the extent that you can't heliccoil it?

[freddie 136]

H, mine had the same trouble so i used a 5mm stainless bolt and carefully screwed it into the end plate if yours is not to far gone maybee you could try the same, the 5mm bolt goes through the timing cover but i dont know if a 6mm would, if it works for you round off the bolt head and put a slot into it for a screw driver,Full over haul of the dynamo at FTW sheffield is approx £140, cheers fred.

[Groily]

Don't think 6mm will pass.
This is a common problem unfortunately John, usually caused by over-tightening (to try to stop the oil leak, which often isn't caused by the joint anyway - see other threads about dynamo oil seals and crankcase joints).
What I have done over the years is drill and tap the dynamo end and make a stepped stud (which will still pass through the t/side crankcase and the timing cover). But it's a horrible area when it starts to go pear-shaped, and one of the few things about my twins I hate deeply. Along with using 2BA for the timing cover screws which is plain bloody stupid - and wouldn't have got past the drawing office, into alloy for chrissake, anywhere else. I wonder sometimes who was thinking what. . . . and then I heretically get on a BSA.
My next step is going to be to make a steel oil seal retainer and better end-plate for the blasted dynamo, that won't strip no matter what. It's ridiculous to have to ditch a perfectly good dynamo just for the lack of mechanical strength in a few fasteners! Lucas would never have done it, I'm sure, had they not been trying to make the same basic body serve on umpteen different machines.
Rant over. Feel better now.

[paul knapp]

The early twins had no provision for a draw bolt/stud to hold the dynamo in place, they only relied on the clamping strap.
With the cork gasket buttered on both sides with silastic and with the lipped seal and seal sleeve in good nick, there won't be any leaks!....well almost

[wilko]

Never knew that Paul! Must consult the archives.

[wilko]

Your right, and two other strange things, crankcase oil deflector 014885? and crankcase washer 011542? Those early twins i've never dealt with.

[paul knapp]

That inclusion of the oil deflector on early twins, which shields the pooling oil at the bottom of crank case from being unnecesarily sloshed around by the crankshaft turbulance, before it's scavenged, and the two crank shaft oil slinger washers, are what I consider the reason I have no over oiling problems either oil burning or excessive oil bleed over into the primary drive necessitating the fitment of an external crank lip seal.

...............well not yet anyway!

[Chazzyb]

quote:
H, mine had the same trouble so i used a 5mm stainless bolt and carefully screwed it into the end plate if yours is not to far gone maybee you could try the same, the 5mm bolt goes through the timing cover but i dont know if a 6mm would, if it works for you round off the bolt head and put a slot into it for a screw driver,Full over haul of the dynamo at FTW sheffield is approx £140, cheers fred.


I dunno about just screwing it in, but I have tapped stripped 2BA holes on Amal carbs to 5mm...

[alanjennings]

Chaps, if you can stop a dynamo on a twin "p====g" oil out, you are a "better man than I am, Gungha Dinn!!